Are differences in hydrocarbon profiles able to mediate strain recognition in German cockroaches (Dictyoptera: Blattellidae)?

Colette Rivault,Ann Cloarec,Leam Sreng

doi:10.14411/eje.2002.055

Abstract

Previous behavioural tests indicated that strain recognition and aggregation behaviour could be induced by cuticular hydrocarbons. The aim of this study was to document and to compare cuticular hydrocarbon profiles between different strains of Blattella germanica (L.) (Dictyoptera: Blattellidae) and to relate variations in the general profile of cuticular hydrocarbons with strain discrimination during behavioural tests. Profiles of different strains were remarkably similar qualitatively but presented slight quantitative differences over the 25 identified components. Important differences were observed in dimethylalkane components and these allowed separation of the strains into two groups using multivariate methods. Although we were not able to demonstrate a relationship between strain discrimination ability and differences in cuticular hydrocarbon profiles, we assumed that cuticular hydrocarbons could play two major roles in B. germanica strains. Less variable hydrocarbon profiles could play a role in species recognition and aggregation behaviour and the more variable part could play a role in strain discrimination.

Highlights

Cuticular lipids comprise a thin layer of polar and apolar material on the outer surface of insect cuticles
These components act as sex pheromones (Schal et al, 1990a, b), aggregation pheromones (Rivault et al, 1998), inter- and intra-species recognition signals and population and caste recognition signals, The use of cuticular lipids in chemosystematics to assess how insects are related is a valuable tool (Howard, 1993)
The aim of this study was to document and to compare cuticular hydrocarbon profiles of different strains of B. germanica collected from different locations and to test whether variations in the general profile of cuticular hydrocarbons could be related to strain recognition abili ties

Summary

Introduction

Cuticular lipids comprise a thin layer of polar and apolar material on the outer surface of insect cuticles. A growing area of interest in insect studies concerns the different roles of cuticular hydrocarbons, which can range from physiological functions, semiochemical functions and behavioural roles to taxonomic and systematic use They act as intra- and interspecific signals for insects (Howard, 1993). Chemical communication based on cuticular hydrocarbons with no apparent glandular origin is a frequent phenomenon among all eusocial insects In insects, these components act as sex pheromones (Schal et al, 1990a, b), aggregation pheromones (Rivault et al, 1998), inter- and intra-species recognition signals and population and caste recognition signals (termites: Brown et al, 1996; Bagnères et al, 1991; ants: Provost et al, 1993; Bonavita-Cougourdan et al, 1989; Nowbahari et al, 1990), The use of cuticular lipids in chemosystematics to assess how insects are related is a valuable tool (Howard, 1993). Seasonal differences within a given species have been reported (Clément, 1986; Bagnères et al, 1990; Dahbi & Lenoir, 1998)

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